More than 75,000 vehicles travel over the Ravenel Bridge daily. One accident, and the entire Charleston traffic system is slowed to a snail’s pace.

About 11 a.m. Tuesday a tanker carrying diesel fuel and a sedan collided, shutting down the bridge to traffic in both directions for the afternoon.

Al Gordon of Mount Pleasant was heading toward Furman University in Greenville about 2 p.m. Tuesday when he ran into blue lights at the foot of the bridge. He drove around trying to find an alternate route to head back up U.S. 17 north to I-526, which was also gridlocked. Tough luck for Spoleto visitors unfamiliar with the area.

“What that tells us is we’ve got a serious transportation problem in the Charleston area,” Gordon said. “You shut down one conduit, and you’ve got gridlock. And here we are sitting with no plans for another north-south alternative.”

Interstates 26 and 526 and numerous feeder roads also slowed to a standstill for much of the day.

The southbound lanes of the bridge closed at 12:30 p.m. and re-opened about 7:20 p.m. The northbound lanes closed about 11 a.m., when the crash occurred and re-opened by 7:50 p.m., according to the Mount Pleasant Police Department.

It’s still unclear what caused the crash. Charleston police spokesman Charles Francis said Tuesday night that the incident report wouldn’t be ready until Wednesday.

He said there were minor injuries involved, but didn’t elaborate.

Mark Ryckman, president of Remtech Engineers in Georgia, has worked about 5,000 fuel spills and said after assessing a picture of the one on the Ravenel Bridge that the crash was ‘an unusual situation,’ with the car likely acting as a plug to the damaged tanker.

He added that because the roads were concrete, the leaked diesel likely wouldn’t interfere with the integrity of the structure.

The bridge deck, or roadway, is supported by 128 cables which hang in a harp-like arrangement from the two towers that reach 575 feet above the water and are connected by the 1,546-foot long main span.

Ryckman guessed it was about an 11,000-gallon tanker involved and said judging by the picture, which was taken sometime around 1 p.m., it looked like under 500-gallons of diesel had leaked out.

Coast Guard Chief Phillip Carpenter confirmed about 100 gallons of diesel fuel leaked from the truck, the majority of which remained on the bridge. He said the Charleston Fire Department was quick to seal the leak from the bridge’s drainage system, preventing a water cleanup.

Hazardous-materials teams from the Charleston and Mount Pleasant fire departments worked to stop the leak.

The bridge closure led to one of the busiest days in the history of the Charleston Water Taxi.

The service runs a 42-person boat and a 20-person ferry across the harbor, between Charleston’s Waterfront Park and Maritime Center and Mount Pleasant’s Patriots Point and the Charleston Harbor Marina.

“I’m running two boats wide open,” said a captain with the service. “I would say we have hundreds of people waiting on us around the harbor right now.”

Several Lowcountry travelers compared the shutdown to last year’s “Ravalanche,” with some complaining of worse traffic.

In late January 2014, chunks of melting ice dropped from the Ravenel Bridge cables and towers in the wake of an unusually fierce winter storm that hit a few days earlier. At least nine people called 911 to report damaged vehicles after the bridge reopened to traffic, and the bridge closed for an additional six hours.

When the bridge re-opened Tuesday, the Charleston Fire Department tweeted a thank you to residents for their patience, adding, “To follow up: 0% chance of falling ice.”

David Waldron, who lives in Mount Pleasant, sat at the Charleston International Airport on Tuesday while trying to figure out the best way home. He grew up in South Africa, traveled all over Europe by train and let his mind imagine what it would be like to build a light rail over the Cooper River.

“That would resolve so much traffic congestion,” he said. “It’s very frustrating that our solution to traffic problems is to build more roads.”